Cant indicator for telescopic rifle sights



H. G. CUMMINS CANT INDICATOR FOR TELESCOPIC RIFLE SIGHTS Filed May 16, 1940 3mal/whor- Harry 6', ummz'n 'EOMETRICAL INSTHUMENIST.

Patented May 27, 1941 UNITED STATES PATENT OFFICE CANT INDICATOR FOR TELES'COPIC RIFLE SIGHTS 6 Claims.

This invention relates to an improved cant indicating attachment for telescopic rifle sights and particularly to the type of telescope sights provided with single cross hairs reticules.

More particularly, it is an air of this invention to provide aiqnclartorfor/telescopic sights including a pendu ving a blade portion at its lower end arranged relatively to the cross hairs of the sight so that the blade will be disposed in line with and concealed by the vertical cross hair when said vertical cross hair is in an exact perpendicular position.

Still another aim of the invention is to provide a cant indicator including a pendulum arranged to function in conjunction with the vertical cross hair of the lsight for indicating the cant of the sight and of the rifle barrel on which it is mounted and which will be disposed behind and concealed by the vertical cross hair when in an exact perpendicular position so that the pendulum will not be visible at the instant that the rifle is discharged and therefore will not interfere with the sighting of the firearm.

Other objects and advantages of the invention will hereinafter become more fully apparent from the following description of the drawing, which illustrates a preferred embodiment of the invention, and wherein:

Figure 1 is a side elevational view showing the cant indicator in an applied position,

Figure 2 is a transverse vertical sectional view taken substantially along the plane of the line 2 2 of Figure 1, and

Figure 3 is a longitudinal vertical sectional View taken substantially along the plane of the line 3-3 of Figure 2.

Referring more particularly to the drawing, wherein like reference characters designate like or corresponding parts throughout the different views, I Il designates generally a portion of the barrel or tube of a telescopic firearm sight and in which is disposed the single cross hairs including the vertical cross hair and the horivzontal cross hair I2. The barrel or tube I0, directly behind the cross hairs, is provided with a transversely disposed elongated slot I3 in the upper portion thereof.

A cylindrical housing I4 is provided with an open arcuately shaped lower end I5 which is mounted on the upper portion of the barrel or tube I n over the slot I3 and connected to the barrel or tube by means of fastenings I6 which extend through apertures in ears I1 of the housing I4 for engaging threaded apertures I l in the barrel or tube III for securing the housing I4 thereon. The upper, open end I9 of the housing I4 is closed by means of a removable cover 2U which is similarly secured by means of fastenings 2| which extend through apertures in ears of the cover 20 and which engage threaded openings in the cylindrical wall of the housing |4. A rod or shaft 22 is secured at its ends by welding or soldering at 23 in the upper portion of the housing I4 and is disposed longitudinally of the barrel I0. A sleeve or hub 24 is rotatably mounted on the rod or shaft 22 between collars 25 which prevent the hub 24 from sliding relatively to the rod. A pendulum, designated generally 26, is secured to and depends from the hub 24. Pendulum 26 includes an arm or hanger 21 which is secured at one end as by means of welding at 23 to the hub 24 and is provided with an enlargement 29 at its opposite end which is secured in a weighted block 30, which is disposed adjacent the lower end of the housing I4. The pendulum 26 also includes a blade 3|, preferably formed of thin spring steel having a hooked upper end 32 which is secured in the block 30 and which depends therefrom through the slot I3 and part way through the barrel I0.

The housing I4, adjacent its lower end, is provided with the diametrically opposed inwardly projecting yieldable stop members 33 which are disposed substantially at right angles to the rod 22 to be engaged by the weighted block 3|) to cushion its swing in either direction toward the cylindrical wall of the housing I4. The hub or sleeve 24 is preferably provided with a lubricating opening 34 by means of which it may be lubricated when the cover 20 is removed.

From the foregoing it will be obvious that the pendulum 2B forms a plumb which will rock relatively to the housing I4, as the latter is tilted, to maintain a perpendicular position. The blade 3| of the pendulum 26 in conjunction with the vertical cross hair II indicates the cant of the sight barrel or tube I0 and of the firearm barrel, not shown, on which the barrel I0 is adapted to be mounted. In sighting a rie equipped with a telescoping sight having the cant indicator, the rifleman in sighting through the barrel I0 will instantly know that the barrel of the rifle is canted if the blade 3| is disposed to either side of the vertical hair so that the rearm can be twisted to bring the blade 3| into alinement with the hair I I. The blade 3| is disposed edgewise of the barrel IIIy and its thicknessis equal to or less than the diameter of the hair II so that when it is in alinement with the hair Il it will be entirely concealed thereby and will therefore not interfere with or confuse the sight or bead being drawn on the target. I'he cross hairs appear to be inverted to the rifleman so that the blade 3| therefore appears to be extending upwardly into the barrel I0.

If desired, the pendulum may be disposed on the opposite side of the cross hairs in which case, when the blade 3| is brought into alinement with the vertical cross hair II, to indicate that the vertical plane of the bore of the firearm is in a perpendicular position, the blade will be coincident with the vertical cross hair and will appear as a part thereof.

Various modifications and changes are contemplated and may obviously be resorted to as only a preferred embodiment of the invention has been disclosed.

I claim as my invention:

1. An attachment for telescopic rifle sights comprising a housing secured to the barrel of a telescopic sight, said barrel having an elongated transversely disposed slot communicating with said housing, said barrel being provided with single cross hairs disposed adjacent to said slot, a shaft xed in said housing, a sleeve rotatably mounted on said shaft, a pendulum secured to and depending from the sleeve, said pendulum including a supporting rod secured to and depending from the sleeve, a weighted block connected to and supported by the rod, and disposed within the housing, and a blade depending from the block through said slot and arranged to swing transversely of the barrel and to aline with the upright cross hair when in a perpendicular position.

2. A cant indicator for telescopic rifle sights comprising a telescopic sight including a tube having cross hairs therein and a transverse slot in its upper portion and adjacent to the cross hairs, a housing mounted on and projecting upwardly from said tube and disposed over said slot, a pendulum mounted in said housing and extending through said slot into the tube, and said pendulum being disposed to aline with the perpendicular cross hair when in a perpendicular position and being constructed and arranged to swing transversely of the sig-ht tube to indicate 4. A cant indicator as in claim 3, said pendulum including a weighted block and a supporting rod disposed within the casing, oppositely disposed yieldable stop members for engaging said Weighted block, and a blade depending from said block and disposed in the barrel and edgewise thereof, said blade being arranged to function with the vertical cross hair to indicate the cant of the sight barrel and the rifle barrel on which it is mounted.

5. In combination with a telescopic rifle sight having cross hairs, the barrel of said sight being provided with an elongated transversely disposed slot in its upper portion and adjacent to and behind the cross hairs, a housing mounted on the barrel over said elongated slot, said housing having a removable cover, a rod secured in said housing, adjacent its upper end, and disposed longitudinally of the sight barrel, a sleeve turnably mounted on the rod, collars carried by the rod and between which the sleeve is disposed to prevent sliding movement of the sleeve relatively to the rod, an arm ixed to and depending from said sleeve, a weighted block secured to the lower end of the arm and disposed adjacent the lower end of the housing, said housing having oppositely disposed inwardly projecting yieldable stop memthe cant of the tube and the rie barreliilihmg 3. A cant indicator for telescopic rifle sights comprising a casing secured to and rising from the barrel of a telescopic sight, said barrel having a transverse slot in its upper portion communicating with the casing, and cross hairs disposed therein and adjacent to said slot, a pendulum mounted in the casing and projecting through said slot into said barrel, and said pendulum being alined with and concealed behind the vertical cross hair when said vertical cross hair is in a perpendicular position.

bers arranged to be engaged by said block to yieldably restrict the swinging movement thereof, and a blade secured to and depending from said block, through said slot, to indicate, in conjunction with the vertical cross hair the cant of the sight barrel and the rie barrel on which it' is l mounted, said blade being disposed behind and concealed by the vertical cross hair when said cross hair is in an upright position.

6. A cant indicator for use with a telescopic rifle sight including a barrel provided with cross hairs, comprising a housing mounted on the barrel and projecting upwardly therefrom, said barrel having an elongated transverse slot in its upper portion communicating with the housing and disposed between the cross hairs and the outer end of the barrel, a shaft secured in the housing and arranged parallel and in the same perpendicular plane as the longitudinal axis of the barrel, a sleeve rotatably mounted on the shaft, a rod secured to said sleeve and depending therefrom, a weight attached to the lower end of the rod and disposed in the lower portion of the housing, and a blade attached to and depending from the weight through the slot into the barrel, said blade being disposed between the outer end of the barrel and the cross hairs and being arranged edgewise of the barrel, and said blade being of a thickness, not greater than the diameter of the vertical cross hair and being concealed thereby when the vertical cross hair is in a perpendicular position.

HARRY G. CUMMINS. 

